Kai Sun of the University of Michigan is a humble physics professor with ambitious goals. “I’m mainly a paper-and-pencil type of theorist, doing analytical calculations mostly,” Sun said. “My interests are pretty broad, but basically searching for new fundamental principles and new phenomena, especially new phenomena and new physics previously believed to be impossible.”
In everyday life, all matter exists as either a gas, liquid, or solid. In quantum mechanics, however, it is possible for two distinct states to exist simultaneously. An ultracold quantum system, for instance, can exhibit the properties of both a fluid and a solid at the same time.
The Synthetic Quantum Systems research group at Heidelberg University has now demonstrated this phenomenon using a new experimental approach, by feeding a small amount of energy into a superfluid. They showed that, in a driven quantum system of this kind, sound waves propagate at two different speeds, which points toward coexisting liquid and solid states, a hallmark of supersolidity. The work is published in the journal Nature Physics.
This surprising and seemingly contradictory behavior of two states of matter existing at the same time does not occur at room temperature. But at ultralow temperatures, quantum mechanics takes over, and matter can exhibit fundamentally different properties. When atoms are cooled to such low temperatures, their wave-like nature is dominant. If brought close enough together, many particles merge into one large wave, known as a Bose-Einstein condensate. This state is a superfluid, a fluid that flows without friction.
A giant anomalous Hall effect (AHE) has been observed in a nonmagnetic material for the first time, as reported by researchers from Japan. This surprising result was achieved using high-quality Cd3As2 thin films, a Dirac semimetal, under an in-plane magnetic field. By modulating the material’s band structure, the team isolated the AHE and traced its origin to orbital magnetization rather than spin, challenging long-held assumptions in condensed matter physics.
In 1879, American physicist Edwin Hall discovered that a voltage develops across a conductor when it carries an electric current in a magnetic field, caused by the sideways deflection of moving charges. This phenomenon, which later became known as the Hall effect, quickly became a hot topic in the field and led to notable advances in the theoretical, experimental, and practical realms alike. Soon after the initial discovery of the Hall effect, scientists noticed that magnetic materials exhibited a similar phenomenon—this was coined the anomalous Hall effect (AHE).
Much more puzzling than the ordinary Hall effect, the AHE has stirred up debate among physicists for decades regarding the true nature of its origin. Some theoretical predictions have even hinted that AHE may be possible even in nonmagnetic materials. However, experimental confirmation of these predictions had never been achieved—until now.
Quantum researchers have deployed a new algorithm to manage noise in qubits in real time. The method can be applied to a wide range of different qubits, even in large numbers.
Noise is the “ghost in the machine” in the effort to make quantum devices work. Certain quantum devices use qubits—the central component of any quantum processor—and they are extremely sensitive to even small disturbances in their environment.
A collaboration between researchers from the Niels Bohr Institute, MIT, NTNU, and Leiden University has now resulted in a method to effectively manage the noise. The result has been published in PRX Quantum.
Salt Typhoon hit 600 organizations in 80 countries since 2019, exploiting router flaws for global espionage.
A rare few, known as hyperthymesics, can recall events from their lives with remarkable precision, linking them to specific dates and vivid sensory details.